Influence of Zinc on the Microstructure and Brittle Phases of Friction Stir Welded Joint of Al / Ti Dissimilar Alloys

2011 ◽  
Vol 413 ◽  
pp. 439-443 ◽  
Author(s):  
Yu Hua Chen ◽  
Liang Yu ◽  
Quan Ni

Titanium alloy TC1 and Aluminum alloy LF6 were butt jointed by friction stir welding (FSW) using zinc as the middle layer material. Influence of zinc on the microstructure and brittle phases were studied. The results show that, the microstructure of the nuclear zone is a mixture structure with Ti alloy particles distributed on Al alloy substrate. At the same time, XRD test results show that there TiAl3 intermetallic compounds and Zn0.69Ti0.31 intermetallic compounds in the nuclear region. The joint which is added zinc as the middle layer material becomes more brittle.

2011 ◽  
Vol 189-193 ◽  
pp. 3266-3269 ◽  
Author(s):  
Yu Hua Chen ◽  
Peng Wei ◽  
Quan Ni ◽  
Li Ming Ke

Titanium alloy TC1 and Aluminum alloy LF6 were jointed by friction stir welding (FSW), and the influence of process parameters on formation of weld surface, cross-section morphology and tensile strength were studied. The results show that, Titanium and Aluminum dissimilar alloy is difficult to be joined by FSW, and some defects such as cracks and grooves are easy to occur. When the rotational speed of stir head(n) is 750r/min and 950r/min, the welding speed(v) is 118mm/min or 150mm/min, a good formation of weld surface can be obtained, but the bonding of titanium/aluminum interface in the cross-section of weld joint is bad when n is 750r/min which results in a low strength joint. When n is 950r/min and v is 118mm/min,the strength of the FSW joint of Titanium/Aluminum dissimilar materials is 131MPa which is the highest.


2021 ◽  
Vol 63 (9) ◽  
pp. 829-835
Author(s):  
Sare Çelik ◽  
Fatmagül Tolun

Abstract AA5754Al alloy is widely used in industry. However, as in the case of all Al alloys, the 5xxx series Al alloys cannot be easily joined through fusion welding techniques. To address this problem, in this study, the effect of double-sided friction stir welding at various tool rotational speeds (450, 710, and 900 rpm), feeding rates (40, 50, and 80 mm × min-1), and tool tilt angles (0°, 1°, 2°) on the welding parameters and mechanical and microstructural characteristics of AA5754 Al alloy was determined. Tensile strength tests and microhardness tests were performed to examine the mechanical properties of the welded specimens. The microstructures of the welded zone were examined by obtaining optical microscopy and scanning electron microscopy images. The tensile test results indicated that the specimens exhibited the highest welding performance of 95.17 % at a tool rotational speed, feed rate, and tool tilt angle of 450 rpm, 50 mm × min-1 and 1°, respectively.


Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2661 ◽  
Author(s):  
Yang Xu ◽  
Liming Ke ◽  
Yuqing Mao ◽  
Qiang Liu ◽  
Jilin Xie ◽  
...  

5A06 Aluminum (Al) alloy and AZ31B magnesium (Mg) alloy with 20 mm thickness were successfully butt joined by friction stir welding. In order to control the composition of Al and Mg alloys along thickness direction, an inclined butt joint was designed in this study. The microstructure and phase identification at the interface of Al/Mg joints were examined using scanning electron microscopy with an energy-dispersive spectroscopy and Micro X-ray diffraction. The results indicated that there were two different formation mechanisms of intermetallic compounds at the interface of thick plate Al/Mg joint. The first was constitutional liquation, and eutectic structure consisting of Al12Mg17 and Mg solid solution existed at the top and upper-middle of the Mg side interface. The second was diffusion reaction, and the two sub-layers of Al12Mg17 and Al3Mg2 formed at the lower middle and bottom of the Mg side interface. In addition, the diffusion thickness values of Al12Mg17 and Al3Mg2 layers decreased gradually from the lower middle to bottom of the Mg side interface. As the position changes from the middle to the bottom near the Mg side interface, the diffusion coefficient of Al3Mg2 phase rapidly decreases from 3.14 × 10−12 m2/s to 6.9 × 10−13 m2/s and the diffusion coefficient of Al12Mg17 phase decreases from 6.8 × 10−13 m2/s to 1.5 × 10−13 m2/s.


Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1115 ◽  
Author(s):  
Yang Zheng ◽  
Xiaomeng Pan ◽  
Yinglei Ma ◽  
Shuming Liu ◽  
Libin Zang ◽  
...  

Friction stir welding (FSW) with a Zr interlayer was employed to join dissimilar alloys of 6061 Al and AZ31 Mg. The microstructures of Al/Mg and Al/Zr/Mg joints were investigated by optical microscopy (OM), scanning electron microscopy (SEM), and energy dispersive X-ray spectrometer (EDS). The results showed that the central part of the Zr interlayer was smashed and intermixed with the base materials in the stir zone, whereas the undamaged part remained stable at the Al/Mg interface. The formation of Al–Mg intermetallic compounds (IMCs) was suppressed by the Zr interlayer due to its synergetic effects of chemical modification and thermal barrier. The electrochemical measurements revealed a differentiated corrosion behavior for each joint, where the corrosion rate of representative regions increased in the order of Al alloy < Mg alloy < heat-affected zone < stir zone. The immersion tests indicated an enhancement in corrosion resistance for the Al/Zr/Mg joint compared with the Al/Mg joint, which is owing to the mitigated galvanic corrosion between the base materials by the Zr interlayer.


2014 ◽  
Vol 1004-1005 ◽  
pp. 168-171
Author(s):  
Hong Yan Du ◽  
Yaj Jang Li ◽  
Juan Wang

Mg/Al dissimilar materials were welded successfully by GTAW with SAlMg-1 and SAlMg-2 welding wire of Mg-Al system. The nice weld shape and free defects of joints are obtained. The test results indicated that continuous lamellar intermetallic compounds is not found The structure of Mg side in the fusion zone is composed of α-Mg solid solution+ β-Al12Mg17eutectic structure and precipitates β-A112lMg17on the grain boundary. The structure in the weld zone is mainly α-Mg solid solution + β-A112lMg17solid solutions. Mg and Al content are stable in the fusion zone of Mg side. However, in the weld zone of Mg side the Mg content is decreased gradually, and the Al content is increased that reaches a stable level in the weld zone of Al side. As a result, when Mg content in the wire can hold a proper level, the intermetallic compounds will be controlled effectively, and the performance of AZ31/7005 welding joint can be improved.


2011 ◽  
Vol 462-463 ◽  
pp. 1212-1217 ◽  
Author(s):  
Amirreza Fahim Golestaneh ◽  
Aidy Ali ◽  
Mehdi Bayat

The present work studies the crack behavior along the surface of the friction stir welded (FSW) joint of 2024-T351 aluminum alloy. The surface engineering of shot peening and skimming are used to enhance the fracture characteristics of the joint. Then multiple crack initiation is detected within FSW zones by scanning electron microscopy, while plastic replication technique is used to monitor the crack propagation. The variation of residual stress is measured (using hole drilling technique) as well as hardness characteristic (using standard method of Vicker) to study the fatigue life of the FSW by two models of Pearson and Nicholls, incorporating crack closure and stress relaxation.


2018 ◽  
Vol 5 (2) ◽  
pp. 4761-4765 ◽  
Author(s):  
Chirag G. Dalwadi ◽  
Anjal R. Patel ◽  
Jaydeep M. Kapopara ◽  
Dhrupal J. Kotadiya ◽  
Nikul D. Patel ◽  
...  

2018 ◽  
Vol 877 ◽  
pp. 98-103
Author(s):  
Dhananjayulu Avula ◽  
D.K. Dwivedi

In this study the effect of process parameters on mechanical and microstructural properties of similar AA6082-T6 joints produced by friction stir welding was investigated. Different samples were produced by varying the transverse welding speeds of the tool from 19 to 75 mm/min and a fixed rotational speed of 635 rpm. A more uniform hardness values in the nugget zone were observed at 48 mm/min welding speed. The lowest hardness values were recorded on nugget zone at all the welding speeds. The increase in welding speed increases ultimate tensile strength and reaches maximum and further increase in welding speed results decrease in tensile strength were observed. The welded joint has highest joint efficiency (52.33 %) obtained at the welding speed of 48 mm/min. Similarly with the increase in welding speed decrease in the percentage elongation were recorded.


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